Overfeed control for printing presses



y 21, 1940- I c. GRUNDHOEFER 2,201,726

OVERFEED CONTROL FOR PRINTING PRESSES NTRX FUGAL CLUTC H Maid 5F: Z @azles nzmdko'qyer Patented May 21, 1940 I UNlT OVERFEED CONTROL FOR PRINTING PRESSES Charles Grundhoefer, Chicago, 111.

Application February 1, 1939, Serial No. 254,103

9 Claims.

* ing the paper in the proper path for assuming the position and register upon the printing cylinder.

A further object of the invention is to provide means which will counteract tendencies of light,

curly, tacky or static-laden paper to buckle or climb the overfeed cam and so get out of register.

Another object of the invention is to eliminate the conventional leaders from the printing cylinder and their tendency to deter the progress of paper constituted or affected in the ways mentioned above, as well as tendencies to scratch or mar the finish of cardboard being fed to the cylinder.

An additional object of the invention is to devise a paper control in the nature of a uniform guiding system operative in harmony with the speed of the paper and effective to lead the same properly irrespective of the speed of the machine. An important object of the invention is to construct the novel control in the form of a unit easily adaptable to any rotary press.

-With the above objects in view, and any others which may suggest themselves from the description to follow, a better understanding of the invention may be had by reference to the. accompanying drawing, in which Fig. 1 is a side view of the novel feed control, partly in section, showing its application in the region of the overfeed; and

Fig. 2 is atop plan view of Fig. 1, partly broken away.

In the feed of the paper sheet to the printing cylinders of rotary presses, and particularly on lithographic work, fairly rapid operating speeds may be maintained where the paper is firm or the ink fast-drying. However, where the paper is light, flimsy, tacky, or apt to curl inherently or by the effect of static, difficulty is had in keeping the sheet in its proper course. Thus, it may have a tendency to climb on the overfeed cam,

or it may buckle from friction or resistance as it encounters the leaders and follows their course. These developments deter the paper to the extent of throwing it out of register uniformly or out of line, these effects ordinarily not beingnoticed until it is time to run a succeeding color, when it is too late. Also, the present feed system makes for disparities in register from one press to another, so thatit is hazardous to run a color job in succeeding presses. It has therefore been my intention to develop a control which eliminates the above deficiencies and hazards and enables the feed to progress uniformly under various conditions and at a desirable rate of speed.

In accordance with the foregoing, specific reference to the drawing indicates a typical printing cylinder for a rotary printing press at H], II being the shaft for the feed, l2 the overfeed cams and i3 the series of grippers associated with the cylinder l0.

As mentioned before, I eliminate the usual series of paper leaders, and in place of these I provide a system of belts employing a shaft l4 suitably journaled in the framework l5 of the press at a point above the printing cylinder I0.

At a point between the shafts M and H and a short distance above the runway |5a over which the paper is fed occurs a cross-shaft It.

The shaft I4 carries a number of integral or tight pulleys ll which are opposite a series of integral or tight pulleys l8 carried by the shaft Hi, the pulleys l1 and 8 carrying endless belts I9. The shaft l4 also carries a series of tight pulleys 26 in alternation with the pulleys l1 and having opposite them a series of loose pulleys 2| mounted on ball-bearings 22 disposed on the shaft II. An endless belt 23 is carried between each set of pulleys 2B and 2|. The shaft l6 also carries a set of tight pulleys |8a in alternation with the pulleys I8.

It is seen from Fig; 1 that the lower runs of the belts l9 and 23 are immediately over the course of the paper sheet 24 on its way to the printing cylinder. It is understood that the overfeed cams |2 are operated jointly in a clockwise direction by the feed shaft I I as seen in Fig. l to feed the paper in the usual manner.

The drive from the feed shaft H to the shaft M is by way of a chain 25 and centrifugal clutch 26. The speed imparted to the pulleys is such as to move the belts l9 and 23 at a rate equal to the surface speed of the cams l2, so that the belts move at the speed .of the paper sheet 24. The pulleys 2| therefore idle on the ball-bearings; and the pulleys I8 and |8a. of the shaft l8 are also for guiding or idling purpose in relation to the lower runs of the respective belts. The centrifugal clutch 26 may be of any design and is intended for the release or disconnection of the belt series when the drive shaft H is not in action.

It will be evident from the above description that I have provided a series of paper guides in the lower runs of the belts 23 which run in harmony with the progress of the paper and shortly above its level so that they counteract any tendency in the paper to follow the rotation of the cams l2 or buckle for any other reason. With the said belt runs traveling at the same speed as the paper, there can be no friction or differential movement between the belt runs and the; paper that may affect or mar the finish or coloring on the paper surface. In order that sufficient guiding units may be employed to assure uniformity of travel along the entire width of the paper sheet, the belts 23 are supplemented by the belts [9 between them, since room is afforded for this purpose as seen in Fig. 2. Thus, the climbing bottom runs of the belts 23 are supplemented by the similarly-operating bottom runs of the belts I9, as suggested in Fig. 2, so that in the climbing zone a better hold of the paper sheet is had and its movement made even until it meets the step 26 of the printing cylinder and assumes the proper position for registration and engagement by the grippers it. Thus, the paper sheet receives traveling guidance in case it has a tendency to curl, buckle or otherwise ,3 move out of its path; and the absence of the leaders insures the undeterred progress of the sheet at all times. Besides, with the control over the entire zone of approach, it is safe to run the press at the requisite speed even when light or unruly paper is used, and whether the same is tacky or static-laden. Further, the belts have a factor of yielclability, which relieves harshness when the paper comes in contact with them; and they adjust themselves to the training of cardboard to the printing cylinder. Finally, it will be seen that the control is in the form of a unit which may be built in or attached to any rotary press and is in this manner interchangeable to permit work to be transferred from one press to another without disparity or error in registration.

While I have described the invention along specific lines, various minor changes and refinements may be made without departing from the principle of the invention, and I desire to consider all such changes and refinements as coming within the scope and spirit of the appended claims.

I claim:

1. In a rotary printing press, the combination with a cylinder, a paper sheet runway adjacent the same, and an overfeed unit for the sheet; of means movable over the path of the sheet between said unit and the cylinder to guide the sheet onto the surface of the cylinder, said means comprising a series of laterally-spaced belts, and a drive to move the lower runs thereof in the direction and at the speed of the sheet.

2. In a rotary printing press, the combination a with a cylinder, a paper sheet runway adjacent the same, and an overfeed unit for the sheet; of means movable over the path of the sheet between said unit and the cylinder to guide the sheet onto the surface of the cylinder, said means comprising a shaft over the cylinder and parallel to the same, a drive from the overfeed unit to the shaft, a series of pulleys carried by the shaft, a series of loose pulleys carried by the overfeed unit opposite the first-mentioned pulleys, and a set of belts trained over alined pulleys of the two series, the drive operating to move the lower runs of the belts in the direction of and at the speed of the sheet.

3. In a rotary printing press having a cylinder, a paper-sheet runway adjacent the same, a shaft over the runway and carrying a longitudinallyspaced series of overfeed cams; a second shaft over the cylinder and parallel to the same and having a series of tight pulleys in alternation with said cams, a drive from the first shaft to the second, a set of loose pulleys carried by the first shaft in alternation with the cams, and a set of belts trained over alined pairs of the tight and loose pulleys, the drive operating to move the lower runs of the belts in the direction of and at the speed of the sheet.

4. In a rotary printing press, the combination with a cylinder, a paper sheet runway adjacent the same, and an overfeed unit for the sheet; of means movable over the path of the sheet between said unit and the cylinder to guide the sheet onto the surface of the cylinder, said means comprising a shaft over the cylinder and parallel to the same, a drive from the overfeed unit to the shaft, a series of pulleys carried by the shaft, a series of loose pulleys carried by the overfeed unit opposite the first-mentioned pulleys, a set of belts trained over alined pulleys of the two series, the drive operating to move the lower runs of the belts in the direction of and at the speed of the sheet, and a clutch interposed in said drive.

5. In a rotary printing press, the combination with a cylinder, a paper sheet runway adjacent the same, and an overfeed unit for the sheet; of means movable over the path of the sheet between said unit and the cylinder to guide the sheet onto the surface of the cylinder, said means comprising a shaft over the cylinder and parallel to the same, a drive from the overfeed unit to the shaft, a series of pulleys carried by the shaft, a series of loose pulleys carried by the overfeed unit opposite the first-mentioned pulleys, a set of belts trained over alined pulleys of the two series, the drive operating to move the lower runs of the belts in the direction of and at the speed of the sheet, and a centrifugal clutch interposed in said drive.

6. The structure of claim 3, said second shaft also carrying a second series of tight pulleys substantially opposite the cams, a third and freelyjournaled shaft between the first and second shafts a third series of tight pulleys carried by the third shaft opposite said second series of tight pulleys, and a second set of belts trained over alined pairs of the second and third pulley series.

'7. The structure of claim 3, said second shaft also carrying a second series of tight pulleys substantially opposite the earns, a third and freely-journaled shaft between the first and second shafts, a third series of tight pulleys carried by the third shaft opposite said second series of tight pulleys, a second set of belts trained over alined pairs of the second and third pulley series, and a fourth set of tight pulleys carried by the third shaft opposite the first series of tight pulleys, the lower runs of the first series of belts utilizing said fourth set of pulleys as idlers to assume a course even with the lower runs of the first series of belts between the second and third shafts.

8. In a rotary printing press, the combination with a cylinder, a paper sheet runway adjacent the same, and an overfeed unit for the sheet; of a guide for the latter comprising means continuously movable from the feed zone of the unit in a path proximate to the course of the sheet to the cylinder surface.

9. In a rotary printing press, the combination with a cylinder, a paper sheet runway adjacent the same, and an overfeed unit for the sheet; of a guide for the latter comprising means continuously movable from the feed zone of the unit in a path proximate to the course of the sheet to the cylinder surface, and at the speed of the feed.

CHARLES GRUNDHOEFER. 

